Automatic electric-circuit breaker



Oct. 16 1923.

J. CLOSSMANN ET AL AUTOMATIC ELECTRIC CIRCUIT BREAKER Filed Dec. 16, 1922 2 sheets-Sheet 1 Oct. 16, 1923.

. 1. CLOSSMANN ET AL AUTOMATIC ELECTRIC CIRCUIT BREAKER Filed Dec. 16, 1922 2 Sheets-Sheet 2 1448/}ATTORNEY Patented Oct. 16, 1923.

JULIUS 'CLOSSMANN AND HEINRICH HALBEBSTADT, OI VIENNA, AUSTRIA.

AUTOMATIC ELECTRIC-CIRCUIT BREAKER.

Application filed December 16, 1922. Serial No. 607,442.

engineer,' and HmNRIoH HALBERSTADT, engineer, both citizens of the Republic of Ausalso under: the in tria, residing at Vienna, in the Republic of Austria, have invented certain new and. useful Improvements in Automatic Electric- Circuit Breakers, of which the following is a specification.

This invention relates to a switch-which is useful both for making and breaking electric circuits and also for service as a safety device or automatic circuit breaker when the permissible current is exceeded. Where such switches have been used heretofore for low currents, separate parts were arranged for each'of these two functions, and such partswere combined together in a suitable manner. The present invention is distinguished from such arrangements in that one and the same part fulfills both functions thus, it is actuated by hand when desired, and it-is actuated also automatically when the permissible current is exceeded.

The switching and safety member consists of a single spring tensioned element, forming a permanent safety element, which does not require to berenewed after its operation. 'The double function of the element is obtained in that it is spring tensioned, and in that the movable contact, is in unstable equilibrium, so that a slight displacement is sufficient to release it, such release being capable of taking lace as well by hand, as

fiiience of the current flowing through it. This influence may be exerted either by the alteration of the length of'the element caused by the Joule effect of the current or by the displacement caused by the magnetic field then produced. In order to obtain the first mentioned influence or result, it is sufiicient to give the element the form of a wire or strip of small crosssection, which when thehighest permissible current is reached. alters its length sufficiently by reason of the change of tempera ture, to effect the release. In order that the magnetic field produced by the current shall act more strongly. the wire or strip is given one or more windings or convolutions.

The invention will be more fully described hereinafter, embodiments thereof shown in the drawing. and the invention will be finally pointed out in the claims.

The drawing shows diagrammatically by way of example several constructural forms of the subject of the invention.

In the accompanying drawings:

Fig. '1 shows in sidevie'w one embodiment of our invention;

Fig. 2 is a plan view of the contact a and shown on Fig. 1;

Fig. 3 is a side view of another form of Fig. 1;

Fig. 4 is a side view of still another form;

Fig. 5 shows a side view-of another embodiment of our invention, in which one or more convolutions are given to the wire;

Fig. 6 is a detail of the contacts;

Fig. 7 shows the same embodiment as that shown in Fig. 5, but now in plan View, and showing several convolutions of the wire;

Fig. 8 shows in plan another embodiment of our invention;

Fig. 9 is a. plan of another embodiment of our invention;

Fig. 10 is a plan of still another embodiment;

Fig. 11 is an elevation of a structure embodying our invention, used to indicate whether current is on or oil i Fig. 12 is another form of such indicator structure; and

Fig. 13 is a side view of a step by step arrangement utilizing our invention.

Similar characters of reference indicate corresponding parts throughout the various views.

Referring to the drawing, Fig. 1 shows a single spring wire or strip a, which is secured at a point I). This is brought by bending it down elastically into the circu t closed position I, where a contact piece or contact plate mounted at its end lies against a stop 0 forming the second contact and is there held fast by the pres sure actin thereon. .In this position the wire or strip a is under spring pressure. If the arm a is moved by hand from the stop contact 0 on which it rests, or. if said contact o is suitably moved, which may be effected by means of 'a finger f (Fig. 5), it'flies back automatically into the circuit open position II.

The wire can also be bent into a loop 8 or winding, which is then suitably insulated and guided on a spool or core 6 In the case shown in Fig. 5 both ends of the wire loop are free. One of them lies against a permanentcontact, for example, it is fixed in one notch of the rack g in which arrangement the tension of the spring can be regulated by selecting the notch to be used. The supply of current takes place, on the one hand, at the stationary end I; of the wire, and on the other hand, at the stop contact 0. The passage of the current through the wire or strip a causes the latter to heat by the Joule effect and the dimensions of the wire or strip are made such that when the maximum permissible current is exceeded, the alteration of length is great enough to lift the contact knob or plate from the stop contact a, of either Fig. 1 or Fig. 5, whereupon it flies back under the influence of its elasticity, or by the effect of the loop into the position in which the circuit is open. It consequentlyacts as a permanent safety device; since the safety element when it acts is not consumed, i. e. it remains continuously in use. Instead of a simple loop 6 as shown in Fig. 5 a spiral e or winding consisting of a plurality of con- 'volutions can be advantageously employed, as indicated in Fig. 7. The wire winding i insulated and supported in a suitable manner as for instance by the spool or core 6 Fig. 2 shows the two contacts 0 bridged by the contact 0 IVhen the contact c is moved out of contact 0 the spring arm a moves the contact 0 into the position indicated by dotted lines in Fig. 1, namely, from position I to position II.

Fig. 3 is a similar arrangement in which the parts 0 and c are held together frictionally.

In Fig. 4 the contact is held in the recess d, of the contact 0, until released therefrom.

Fig. 6 shows the contacts 0 and 0 used in Fig. 5, frictionally held.

In the constructional forms shown in Figs. 5, 7 8, 9 and' 10, the influence of the magnetic field of the winding comes into operation.

In Fig. 8 we have shown another application of our invention. In order to enable exactly the same dimensions of the wire, or of the wire spiral, to be used with different maximum currents, a resistance 72. can be connected in parallel to the wire spiral. The stop or contact ismade in two parts 0 and 0 which are bridged by the contact knob or plate 0 of the wire element, in order 'to keep the resistance it only under the ac tion of the current in the circuit closed position. The wire spiral is ,then only acted upon by the shunt current flowing in par allel with that in the resistance It. The alteration of the permissible maximum value of the current takes place by interchanging the resistance It or a choking coil h which is in parallel with the coil 6, without however, any alteration in the coil e itself. Instead of an ohmic resistance as shown in vFig. 10, there can alsobe connected as the shunt, a condenser 71, as shown in Fig. 9. These serve for exactly regulatble stoppage or blocking of the movable member of the circuit breaker or any other forcible influence, the wire itself or a part thereof can be made of a fusible alloy which acts as a fusible cut-out or fuse; when excess current is used. By suitable choice of the fusible cut-out, the latter can be arranged so as never to blow out in normal cases, since the extension of length of the arm a or a which effects the instantaneous release of the automatic circuit breaker, takes place at a temperature lying below that at which the fuse blows. The melting of the fusible cutout only takes place when the operation of the circuit breaker is forcibly prevented. This obviously may render necessary a replacement of the fuse wire or of the section of the wire in question.

The above described invention provides a switch with a quite simple permanent safety device without additional parts and without requiring renewal of the parts when the safety device acts, and it is arranged in such an easily inspected manner that at any time one can immediately see from the outside whether it has acted. If the switch is quite enclosed, the end of the wire can be provided with an indicating signal which becomes visible through an aperture. A casing -m has an aperture a through which is visible an indicator 0 movable on a pivot 1--by a lever g which is struck by the contact 0 A stop r is provided to limit the movement of the lever q. The arm (a is in circuit open position in full lines and in circuit closed position in dotted lines. A similar but electrical indicator is shown in Fig. 12, where the contact 0 closes a branch circuit 8 having a lamp t to indicate that the arm a is in circuit open position. Thus the use of a separate fuse panel on a switch board is rendered unnecessary, since this is completely replaced bythe circuit breaker itself. oreover, many further advantages are obtained by the use of the improved automatic circuit breaker. Thus the dimensions of the wire, the diameter of the coil, and the'number of turns of .the coil may be such that the opening of the circuit only takes place after a definite time, so that a time limit switch is obtained.

The improved apparatus is adapted for extensive application, since it can be used not only as an automatic circuit breaker, but also in cases where a step-by-step automatically released operation of a switch arm Ill) between two contacts or over a series of contacts which must be of suitable shape, takes place. An embodiment thereof is shown in Fig. 13.- in which a plurality of contacts are utilized. Step by step the contact 0 with the arm a is moved over the successive contact 0.

While we have herein shown and described several practical embodiments of the invention it is to be-understood that changes may be made therein without departing from the spirit and scope of the invention as claimed.

What we claim is: l i

1. An automatic circuit breaker, comprising a contact, a unitary spring and homogeneous current conducting member for completing the circuit with said contact, said unitary spring and current conducting member upon receiving a current above a definite predetermined quantity moving to open circuit position.

2. An automatic circuit breaker, comprising a contact and a unitary spring and homogeneous current conducting member, its own spring action holding it in position to com-- plete the circuit with said contact under normal current flow, and moving it out of said position for opening the circuit under a current flow greater than a predetermined quantity. ,1

3. An automatic circuit breaker, comprising a contact and a unitary spring and homo-- geneous current conducting member, its own spring tension holding it in position for completing the circuit with said contact under normal current flow, and moving it out of said position for opening the circuit when longitudinally extended under a current flow greater than a predetermined quantity.

4. An automatic circuit breaker, comprising a contact, a unitary spring and homogeneous current conducting member, its own spring action holding it in position to complete the circuit in said contact under normal current flow, and moving it out of said position for opening the circuit under a current flow greater than a predetermined quantity, and a convolution interposed in circuit with said member and formed in the length of said member. v

5. An automatic circuit breaker, comprising a contact, a unitary spring and homo geneous current conducting member, its own spring action holding it in position to complete the circuit with said contact under normal current flow, and moving it out of said position for opening the circuit under a current flow greater than a predetermined quantity, a plurality of convolutions in circuit with said member/and formed in the length of said member, and means for mechanically varying the spring tension of said conducting member. 7

6. An automatic circuit breaker comprising a contact, a unitary spring and homogeneous current conducting member, its own spring action holding it in position to complete the circuit with said contact under normal current flow, and moving it out of said position for opening the circuit under a current flow greater than a 1)redctermined quantity, a contact member on the free end of said unitary spring and current conducting member, means for holding the other free end of said unitary spring and current conducting member, and a plurality of convolutions interposed between the free ends of said unitary spring and current conducting member.

7. An automatic circuit breaker. comprising a contact, a unitary spring and homogeneous current conducting member, its own spring action holding it in position to com plete the circuit with said contact under normal current flow, and moving it out of said position for opening the circuit under a curient flow greater than a predetermined quantity, a contact member on the free end of said unitary spring and current conducting member, means for holding the other free end of saidunitary spring and current conducting member, a plurality of convolutions interposed between the free e'nds of said unitary spring and current conducting member,

and means for varying the tension of said unitary spring and current conducting member.

8. In combination with a circuit breaker comprising a contact and a unitary spring and homogeneous current conducting member, its own spring action holding it in position to complete the circuit with said contact under normal current flow, and moving it out of said position for opening the circuit under a current flow greater than a predetermined quantity, a circuit shunted in respect to said circuit breaker and a resistance in said shunt circuit.

9. An automatic circuit breaker, comprising a contact and a unitary spring and homogeneous current conducting member for completing the circuit with said contact, said unitary spring and current conducting member upon receiving a current above a definite predetermined quantity being adapted to move to open circuit position, and being formed of a material which fuses when prevented from moving to open circuit position upon receiving a current above a definite predetermined quantity.

10. An automatic circuit breaker, comprising a contact, a second contact movable in respect to the first contact, and a homogeneous current carrying arm perpendicularly arranged to the movable contact, having spring means for rapidly moving the arm away from the first contact. K

11. An automatic circuit breaker, comprising a' stationary'vertically arranged contact member, a movable contact member. mov able along the stationary contact member, a resilient homogeneous current carrying Ill til)

. tact member.

13. An automatic circuit breaker, comprising a contact, a second contact movable in respect thereto, a resilient homogeneous current carrying rod at right angles to the movable contact, said rod moving the movable contact against the fixed contact when in closed circuit position and under the influence of an electric current less than a pre determined amount, and moving the movable contact away from the fixed contact when under the action of a current greater than a predetermined amount.

14. An automatic circuit breaker, comprising a contact arranged vertically, and

having a flat vertical surface and a surface curved away from the flat surface, a movable contact, a rod perpendicular to the movable contact at a point substantially in a line perpendicular to the vertical surface of the fixed contact to permit the movable con tact to pass along the curved line of the other contact, and move the movable contact away from the other contact to current open position, means for drawing the movable contact tightly against the other contact when in circuit closed position when under the action of an electric current less than a predetermined amount, and moving the movable contact away from the other contact when under the action of an electric current greater than a predetermined amount.

15. An automatic circuit breaker, comprising a contact, a second contact movable in respect to the first, resilient homogeneous current carrying means for frictionally holding the movable contact to the other contact under spring tension, said frictional hold being released when the current eX- ceeds a predeterm ned amount, and swinging it into open position by the action of the spring tension.

16. An automatic circuit breaker, comprising a contact. a second contact movable in respect to the first, resilient homogeneous current carrying means for frictionally holding the movable contact to the first contact under spring tension, said frictional hold being released when the current exceeds a predetermined amount, and swinging it into open position by the action of the spring tension. and a plurality of convolutions arranged at right angles to the holding means.

17. An automatic circuit breaker, comprising afixed contact, a movable contact, and a unitary spring element which expands longitudinally under the influence of excess current flow, and whose natural spring action holds the movable contact in the closed circuit position on the fixed contact, and provides the necessary force for moving the movable contact rapidly away from its position on the fixed contact into circuit open position, when the definite current is exceeded, whereb nthe movable'contact is lifted from the xed contact and the rapid movement of the movable contact into open circuit position takes place.

18. An automatic circuit breaker, comprising contacts adapted to make and breaka circuit, a unitary spring and current conducting member having one end on one of said contacts and adapted to be substantially uniformly longitudinally elongated under excess current flow, its own spring action holding its contact on the other contact to complete the circuit under normal current flow, and moving its contact out of contactual position for opening the circuit under a current flow greater than the predeterm ned quantity, and means for holding the other end of said spring member adjustably in position.

19. An utomatic circuit breaker, a switch n ember elastic and current carrying and consisting of a spiral coil wound in the form of asolenoid and having freely projecting end arms. whereby the influence of the current on all the windings acts by the longitudinal movement of the end arm corresponding to the total effect, by reason of the action of the heat generated by the current and also by the magnetic field produced.

20. An automatic circuit breaker, comprising a contact, and a unitary spring and current conducting member for completing the circuit with said contact, its own spring action under normal current flow holding it in closed circuit position with the contact and moving it to open circuit position in respect to said contact under excess current flow.

21. An automatic circuit breaker,comprising a contact, a unitary spring and current conducting member for completing the circuit with said contact, its own spring action under normal current flow holding it in closed circuit position with the contact and moving it to open c rcuit position in respect to said contact under excess circuit flow, and a convolution in said member and in electrical circuit therewith. I

22. An automatic circuit breaker, comprising a contact, a second contact adapted to contact with the first contact, and a. unitary spring and current conducting member perpendicular to the second contact for moving it into and out contact with the first contact,

its own spring action on normal current flow holding the second contact in closed position with the first contact, and moving the second contact to open circuit position in respect to the first contact on excess current flow. I

23, An automatic circuit breaker, comprising a contact, a second contact adapted to contact with the first contact, a unitary spring and current conducting member perpendicular to the second contact for moving it into and out of contact with the first contact, its own spring action under normal current flow holding the second contact in closed position with the first contact, and moving the second contact to ope-n circuit position in respect to the first contact under excess current flow, and meansfor varying the spring tension of said member.

24. An automatic circuit breaker, comprising a first contact having an effective contact surface and a curved portion extending away therefrom, a second contact adapted to contact With the effective contact-surface and being adapted to be moved along the curved portion thereof, and a unitary spring and current conducting member fixed to the second contact for moving it into an effective contact position with the first contact,

face, increasing the spring tension of the member, the spring tension of the member holding the second contact in pos'tion along the effective contact surface thereot, under normal current flow, and moving it out of position and away from the first contact under excess current flow,

2."). .\n automatic circuit breaker. comprising a contact member. an electric current conducting: arm for said contact member, an electric current conducting solenoid shaped convolution for said arm, and in circuitwith said arm and contact member, the axis of the convolution being perpendicular to the arm and to the path of movement of the arm. and a second contact adapted to contact with the first contact.

In testimony whereof we have hereunto set our hands.

JULIUS CLOSSMANN. HEINRICH HALBERSTADT Witnesses CARL TONDENBERG, LUDWIG BURmo. 

